The present invention relates to an arrangement for pneumatic transporting of materials. More particularly it relates to an arrangement for transporting such materials which have a tendency to form deposits.
Different materials, such as, for example, carbon black utilized in the manufacture of rubber, are very greasy and therefore have a tendency to stick to inner walls of transport conduits and to form deposits thereon. This results in that the transport conduit after very short time, even after some minutes following the beginning of operation, becomes obstructed by the material to be transported and further transportation of the material through the conduit is thereby interrupted. This is characteristic for all pneumatic transport systems, and particularly for the systems which comprise transport conduits having curved sections.
It is known that to prevent such interruption of the operation of pneumatic transport systems comprising flexible transport conduits, an operator must knock against sections of the flexible transport conduit which are vulnerable to this clogging, so as to dislodge the material which form the deposits in inner walls of these sections. However, this is fairly difficult, time consuming and requires the constant presence of an operator during the entire operation of the transport system.
To avoid the formation of the deposits of the material and to eliminate manual removal of the same, it has been proposed to provide the vulnerable sections of the flexible transport conduits with vibrators, which continuously transmit vibrations to these sections during the entire operation of the transport system and therefore prevent sticking of the transported material on the inner walls of the transport conduits. In this case the transport conduits, which often have considerable length and comprise a plurality of curved sections, are also complex construction and so expensive that such pneumatic transport systems are not used in industry.
It has been further proposed in the art to clean rigid transport pipelines of pneumatic transport systems by means of flexible pneumatic conduits located inside the rigid pipelines. In this case the rigid tube and the flexible inner conduit is constituted of separate sections, which sections have end flanges for connecting the sections to one another. An outer surface of the flexible conduit is provided with projections spaced from one another and forming a plurality of recesses between the inner surface of the rigid tube and the outer surface of the flexible conduit. Air is fed between the above mentioned surfaces, deforms the flexible conduit and removes the material from the inner surface thereof. This construction is also very complex and expensive. In addition, it is required to form each curved section of the tube as a separate part and thereafter to connect it to adjacent sections. It should be also noted that this construction is applicable exclusively for use with rigid transport conduits.